抄録
This article describes the characteristics of running and sprinting from the viewpoint of kinematics and mechanical energy. Mechanical stress on the body induced by running does not always increase at faster running speed. Mechanical stress on the body when running is affected by the conversion of mechanical energy and momentum. In instruction on running in the field of physical therapy, it is not necessary to decide the grade of running as to speed. It is necessary to prescribe running while predicting mechanical stress on the body, and thinking about the conversion of mechanical energy and momentum.